Quote:
Originally Posted by Don Pensack
I built a pair of binoculars from scopes similar to the pic of the 5" SCTs.
The true field of view is extremely narrow.
For two reasons:
1) the extra long back focus raises the f/ratio and focal length and decreases the maximum true field in an SCT when adding all that length to the rear.
2) any time a longer tube is added to the rear of any scope, the true field shrinks. Want an example? Look at any view through a 10cm long tube. Then look at the same scene with a 20cm long tube. The true field of view shrinks simply from that.
I'd bet the maximum field went from 1° to less than 1/2° on those SCTs when made into binoculars.
There would be much less effect when doing the same to a pair of refractors. If you're tempted to do so, definitely use refractors.
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A pair of FS102s would make for a very nice binoscope, I am going to see if next year's budget allows for an extra TOA130 purchase
and the EMS-UL or UXL from Tatsuro but I would have to borrow a mount from MattT...
